Class: Rex::Proto::NTLM::Crypt

Inherits:
Object
  • Object
show all
Defined in:
lib/rex/proto/ntlm/crypt.rb

Constant Summary collapse

CONST = 
Rex::Proto::NTLM::Constants
BASE = 
Rex::Proto::NTLM::Base
@@loaded_openssl = 
false

Class Method Summary collapse

Class Method Details

.apply_des(plain, keys) ⇒ Object

Raises:



85
86
87
88
89
90
91
92
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 85

def self.apply_des(plain, keys)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  dec = OpenSSL::Cipher::DES.new
  keys.map do |k|
    dec.key = k
    dec.encrypt.update(plain)
  end
end

.decrypt_sessionkey(encrypted_session_key, user_session_key) ⇒ Object

Raises:



382
383
384
385
386
387
388
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 382

def self.decrypt_sessionkey(encrypted_session_key, user_session_key)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  cipher = OpenSSL::Cipher::Cipher.new('rc4')
  cipher.decrypt
  cipher.key = user_session_key
  cipher.update(encrypted_session_key)
end

.des_56_to_64(ckey56s) ⇒ Object 



71
72
73
74
75
76
77
78
79
80
81
82
83
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 71

def self.des_56_to_64(ckey56s)
  ckey64 = []
  ckey56 = ckey56s.unpack('C*')
  ckey64[0] = ckey56[0]
  ckey64[1] = ((ckey56[0] << 7) & 0xFF) | (ckey56[1] >> 1)
  ckey64[2] = ((ckey56[1] << 6) & 0xFF) | (ckey56[2] >> 2)
  ckey64[3] = ((ckey56[2] << 5) & 0xFF) | (ckey56[3] >> 3)
  ckey64[4] = ((ckey56[3] << 4) & 0xFF) | (ckey56[4] >> 4)
  ckey64[5] = ((ckey56[4] << 3) & 0xFF) | (ckey56[5] >> 5)
  ckey64[6] = ((ckey56[5] << 2) & 0xFF) | (ckey56[6] >> 6)
  ckey64[7] =  (ckey56[6] << 1) & 0xFF
  ckey64.pack('C*')
end

.encrypt_sessionkey(session_key, user_session_key) ⇒ Object

Raises:



374
375
376
377
378
379
380
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 374

def self.encrypt_sessionkey(session_key, user_session_key)
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  cipher = OpenSSL::Cipher::Cipher.new('rc4')
  cipher.encrypt
  cipher.key = user_session_key
  cipher.update(session_key)
end

.gen_keys(str) ⇒ Object 



67
68
69
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 67

def self.gen_keys(str)
  str.scan(/.{7}/).map{ |key| des_56_to_64(key) }
end

.is_hash_from_empty_pwd?(arg) ⇒ Boolean

this function will check if the net lm response provided correspond to en empty password

Returns:

  • (Boolean)

Raises:



235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 235

def self.is_hash_from_empty_pwd?(arg)
  hash_type = arg[:type]
  raise ArgumentError,"arg[:type] is mandatory" if not hash_type
  raise ArgumentError,"arg[:type] must be lm or ntlm" if not hash_type  =~ /^((lm)|(ntlm))$/

  ntlm_ver = arg[:ntlm_ver]
  raise ArgumentError,"arg[:ntlm_ver] is mandatory" if not ntlm_ver

  hash = arg[:hash]
  raise ArgumentError,"arg[:hash] is mandatory" if not hash

  srv_chall = arg[:srv_challenge]
  raise ArgumentError,"arg[:srv_challenge] is mandatory" if not srv_chall
  raise ArgumentError,"Server challenge length must be exactly 8 bytes" if srv_chall.length != 8

  #calculate responses for empty pwd
  case ntlm_ver
  when CONST::NTLM_V1_RESPONSE
    if hash.length != 24
      raise ArgumentError,"hash length must be exactly 24 bytes "
    end
    case hash_type
    when 'lm'
      arglm = { 	:lm_hash => self.lm_hash(''),
          :challenge => srv_chall}
      calculatedhash = self.lm_response(arglm)
    when 'ntlm'
      argntlm = { 	:ntlm_hash =>  self.ntlm_hash(''),
          :challenge => srv_chall }
      calculatedhash = self.ntlm_response(argntlm)
    end
  when CONST::NTLM_V2_RESPONSE
    raise ArgumentError,"hash length must be exactly 16 bytes " if hash.length != 16
    cli_chall = arg[:cli_challenge]
    raise ArgumentError,"arg[:cli_challenge] is mandatory in this case" if not cli_chall
    user = arg[:user]
    raise ArgumentError,"arg[:user] is mandatory in this case" if not user
    domain = arg[:domain]
    raise ArgumentError,"arg[:domain] is mandatory in this case" if not domain

    case hash_type
    when 'lm'
      raise ArgumentError,"Client challenge length must be exactly 8 bytes " if cli_chall.length != 8
      arglm = {	:ntlmv2_hash =>  self.ntlmv2_hash(user,'', domain),
          :challenge => srv_chall }
      optlm = {	:client_challenge => cli_chall}
      calculatedhash = self.lmv2_response(arglm, optlm)[0,16]
    when 'ntlm'
      raise ArgumentError,"Client challenge length must be bigger then 8 bytes " if cli_chall.length <= 8
      argntlm = { 	:ntlmv2_hash =>  self.ntlmv2_hash(user, '', domain),
          :challenge => srv_chall }
      optntlm = { 	:nt_client_challenge => cli_chall}
      calculatedhash = self.ntlmv2_response(argntlm,optntlm)[0,16]
    end
  when CONST::NTLM_2_SESSION_RESPONSE
    raise ArgumentError,"hash length must be exactly 16 bytes " if hash.length != 24
    cli_chall = arg[:cli_challenge]
    raise ArgumentError,"arg[:cli_challenge] is mandatory in this case" if not cli_chall
    raise ArgumentError,"Client challenge length must be exactly 8 bytes " if cli_chall.length != 8
    case hash_type
    when 'lm'
      raise ArgumentError, "ntlm2_session is incompatible with lm"
    when 'ntlm'
      argntlm = { 	:ntlm_hash =>  self.ntlm_hash(''),
          :challenge => srv_chall }
      optntlm = {	:client_challenge => cli_chall}
    end
    calculatedhash = self.ntlm2_session(argntlm,optntlm).join[24,24]
  else
    raise ArgumentError,"ntlm_ver is of unknow type"
  end
  hash == calculatedhash
end

.lanman_des(password, challenge) ⇒ Object

Synonym of lm_response for old compatibility with lib/rex/proto/smb/crypt



141
142
143
144
145
146
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 141

def self.lanman_des(password, challenge)
  lm_response({
    :lm_hash => self.lm_hash(password),
    :challenge => challenge
  })
end

.lanman_session_key(pass, srvchall, opt = {}) ⇒ Object

Used when LanMan Key flag is set



359
360
361
362
363
364
365
366
367
368
369
370
371
372
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 359

def self.lanman_session_key(pass, srvchall, opt = {})
  if opt[:pass_is_hash]
    halfhash = pass[0,8]
  else
    halfhash = lm_hash(pass.upcase[0,7],true)
  end
  plain = self.lm_response({
    :lm_hash => halfhash[0,7],
    :challenge => srvchall
  }, true )
  key = halfhash  + ["bdbdbdbdbdbd"].pack("H*")
      keys = self.gen_keys(key)
     	apply_des(plain, keys).join
end

.lm_hash(password, half = false) ⇒ Object 



94
95
96
97
98
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 94

def self.lm_hash(password, half = false)
  size = half ? 7 : 14
  keys = gen_keys(password.upcase.ljust(size, "\0"))
  apply_des(CONST::LM_MAGIC, keys).join
end

.lm_response(arg, half = false) ⇒ Object

Create the LANMAN response



127
128
129
130
131
132
133
134
135
136
137
138
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 127

def self.lm_response(arg, half = false)
  begin
    hash = arg[:lm_hash]
    chal = arg[:challenge]
  rescue
    raise ArgumentError
  end
  chal = BASE::pack_int64le(chal) if chal.is_a?(Integer)
  if half then size = 7 else  size = 21 end
  keys = gen_keys hash.ljust(size, "\0")
  apply_des(chal, keys).join
end

.lmv1_user_session_key(pass, opt = {}) ⇒ Object

Used when only the LMv1 response is provided (i.e., with Win9x clients)



316
317
318
319
320
321
322
323
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 316

def self.lmv1_user_session_key(pass, opt = {})
  if opt[:pass_is_hash]
    usk = pass[0,8]
  else
    usk = self.lm_hash(pass.upcase[0,7],true)
  end
  usk.ljust(16,"\x00")
end

.lmv2_response(arg, opt = {}) ⇒ Object

Raises:



206
207
208
209
210
211
212
213
214
215
216
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 206

def self.lmv2_response(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  key = arg[:ntlmv2_hash]
  chal = arg[:challenge]

  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  cc   = opt[:client_challenge] || rand(CONST::MAX64)
  cc   = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

  OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, key, chal + cc) + cc
end

.lmv2_user_session_key(user, pass, domain, srv_chall, cli_chall, opt = {}) ⇒ Object Also known as: ntlmv2_user_session_key

Used when the LMv2 response is sent

Raises:



347
348
349
350
351
352
353
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 347

def self.lmv2_user_session_key(user, pass, domain, srv_chall, cli_chall, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  ntlmv2_key = self.ntlmv2_hash(user, pass, domain, opt)
  hash1 = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_key, srv_chall + cli_chall)
  OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_key, hash1)
end

.make_weak_sessionkey(session_key, key_size, lanman_key = false) ⇒ Object 



390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 390

def self.make_weak_sessionkey(session_key,key_size,lanman_key = false)
  case key_size
  when 40
    if lanman_key
      return session_key[0,5] + "\xe5\x38\xb0"
    else
      return session_key[0,5]
    end
  when 56
    if lanman_key
      return session_key[0,7]  + "\xa0"
    else
      return session_key[0,7]
    end
  else #128
    return session_key[0,16]
  end
end

.ntlm2_session(arg, opt = {}) ⇒ Object

Raises:



218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 218

def self.ntlm2_session(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  passwd_hash,chal = arg[:ntlm_hash],arg[:challenge]
  if not (passwd_hash and chal)
    raise RuntimeError, "ntlm_hash and challenge are required"
  end

  cc = opt[:client_challenge] || rand(CONST::MAX64)
  cc = BASE::pack_int64le(cc) if cc.is_a?(Integer)

  keys = gen_keys(passwd_hash.ljust(21, "\0"))
  session_hash = OpenSSL::Digest::MD5.digest(chal + cc)[0,8]
  response = apply_des(session_hash, keys).join
  [cc.ljust(24, "\0"), response]
end

.ntlm2_session_user_session_key(pass, srv_chall, cli_chall, opt = {}) ⇒ Object

Used when NTLMv1 authentication is employed with NTLM2 session security

Raises:



338
339
340
341
342
343
344
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 338

def self.ntlm2_session_user_session_key(pass, srv_chall, cli_chall, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  ntlm_key = self.ntlmv1_user_session_key(pass, opt )
  session_chal = srv_chall + cli_chall
  OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlm_key, session_chal)
end

.ntlm_hash(password, opt = {}) ⇒ Object

Raises:



100
101
102
103
104
105
106
107
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 100

def self.ntlm_hash(password, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
  pwd = password.dup
  unless opt[:unicode]
    pwd = Rex::Text.to_unicode(pwd)
  end
  OpenSSL::Digest::MD4.digest(pwd)
end

.ntlm_md4(password, challenge) ⇒ Object

synonym of ntlm_response for old compatibility with lib/rex/proto/smb/crypt



157
158
159
160
161
162
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 157

def self.ntlm_md4(password, challenge)
  ntlm_response({
    :ntlm_hash =>  self.ntlm_hash(password),
    :challenge => challenge
  })
end

.ntlm_response(arg) ⇒ Object 



148
149
150
151
152
153
154
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 148

def self.ntlm_response(arg)
  hash = arg[:ntlm_hash]
  chal = arg[:challenge]
  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  keys = gen_keys(hash.ljust(21, "\0"))
  apply_des(chal, keys).join
end

.ntlmv1_user_session_key(pass, opt = {}) ⇒ Object

This variant is used when the client sends the NTLMv1 response

Raises:



326
327
328
329
330
331
332
333
334
335
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 326

def self.ntlmv1_user_session_key(pass, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  if opt[:pass_is_hash]
    usk = pass
  else
    usk = self.ntlm_hash(pass)
  end
  OpenSSL::Digest::MD4.digest(usk)
end

.ntlmv2_hash(user, password, domain, opt = {}) ⇒ Object

This hash is used for lmv2/ntlmv2 response calculation

Raises:



110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 110

def self.ntlmv2_hash(user, password, domain, opt={})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  if opt[:pass_is_hash]
    ntlmhash = password
  else
    ntlmhash = ntlm_hash(password, opt)
  end
  # With Win 7 and maybe other OSs we sometimes get the domain not uppercased
  userdomain = user.upcase  + domain
  unless opt[:unicode]
    userdomain = Rex::Text.to_unicode(userdomain)
  end
  OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmhash, userdomain)
end

.ntlmv2_response(arg, opt = {}) ⇒ Object

Raises:



164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
 
# File 'lib/rex/proto/ntlm/crypt.rb', line 164

def self.ntlmv2_response(arg, opt = {})
  raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

  key, chal = arg[:ntlmv2_hash], arg[:challenge]
  if not (key and chal)
    raise ArgumentError , 'ntlmv2_hash and challenge are mandatory'
  end

  chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
  bb   = nil

  if opt[:nt_client_challenge]
    if opt[:nt_client_challenge].to_s.length <= 8
      raise ArgumentError,"nt_client_challenge is not in a correct format "
    end
    bb = opt[:nt_client_challenge]
  else
    if not arg[:target_info]
      raise ArgumentError, "target_info is mandatory in this case"
    end

    ti = arg[:target_info]
    cc = opt[:client_challenge] || rand(CONST::MAX64)
    cc = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

    ts = opt[:timestamp] || Time.now.to_i

    # Convert the unix timestamp to windows format
    #   epoch -> milsec from Jan 1, 1601
    ts = 10000000 * (ts + CONST::TIME_OFFSET)

    blob = BASE::Blob.new
    blob.timestamp = ts
    blob.challenge = cc
    blob.target_info = ti

    bb = blob.serialize
  end

  OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, key, chal + bb) + bb
end